Improvement in apparatus for feeding pulverized fuel to metallurgical and other furnaces



Jaim. fifi Zi F@ pfiffig Pif/MHZ MZ ZZ/Z i0 551mm Paented Oct. 17, 18711.

U Iren for D? Mdm UNITED STATES 'r OFFICE.

JOHN Y. SMITH, OF PITTSBURG, PENNSYLVANIA.

IMPROVEMENT IN APPARATUS FDR FEEDING PULVERIZED FUEL T0 NiETALLUHGICAL AND THEH FUHNACES.

Specication forming part cf Letters Patent No. 120,008, dated October' 17, i871.

To all whom 'it may concern:

Be it known that I, JOHN Y. Sm'rH, of Pittsl burg, in the county of Allegheny and State of Pennsylvania, have invented certain Improvements in Apparatus for Feeding` Comminuted Fuel to Metallurgie and. other Furnaces; and I do hereby declare that the following is a full, clear, and exact description thereof', reference being had to the annexed drawing making part of this specification, in which- Figure 1 is a perspectiveview. Fig. 2 isa vertical longitudinal section. Fig. 3 is a transverse section.

The same letters are used in all the figures in the designation of identical parts.

The object of this apparatus is to feed finelypowdered coal to be ignited and burned while floating in the atmosphere, and to provide in connection therewith means for regulating the quantity of airentering with the comminuted fuel, and also to provide for the admixture of gas, oil, or other iuids that may be for any purpose needed in 4conjunction with the said pulverulent material. In the annexed drawing, A and B are com- 4partments of a case or cases for the revolving fans C E and F, all attached to the shaft D. The fans are all formed as shown in Figs. 2 and 3. The fan C is driven by a jet of steam entering at C and impinging against the iioats, es-

caping through the pipe M. This fan is intended to give motion to the other parts of the-mechanism. The case or compartment B is subdivided by a partition, B', which prevents the passage of air between the two subdivisions. The shaft D should pass through a stuffing-box in this partition. The fan E is intended to force the pulverulent fuel through the exit-pipe E. The fan F is for the purpose of supplying an air-blast to maintain a brisk fire ofordinary solid fuel in front of the mouth of the pipe E to ignite the pulverized fuel as it is driven over it. A pulley on the projecting end of the shaft D communicates motion to the pulley H on the feed-shaft K. This is a spirally-flanged shaft which may be like the shank of an auger-bit, and is intended to feed the comminuted fuel from the hopper I into the pipe L, through which it will be drawn by the suction of the fan E into the compartment containing said fan. This pipe must be closely fitted to the hopper and fan-case, as in this apparatus it is carefully provided that no air shall enter with the pulverized fuel into the them with the coal-powder to drive them forward together into the furnace. An annular collar, O,

is placed on the pipe E with openings O1 O2 etc., through which air or gas in regulated quantities may be mingled with the pulverulent fuel. In certain operations petroleum or other conibustible liquids may be needed to be mingled with the fuel, and such substances may also be discharged in regulated quant-ities into the pipe E by means of these openings.

Other devices may be substituted for the hopper and the feed-shaft. I have used for this purpose an elastic bag of India rubber to feed the coal into the injector; said bag being' attached below to the case and above to a hopper, with a device connected at the middle to twist it slightly, first in one direction and then in the other, thereby preventing the packing of the coal-dust.

In operating this apparatus hi gh-pressure steam is introduced through the pipe C. The hopper being constantly supplied with coal is kept full all the time, so that no air may pass in with the coal except such inevitable quantities as will be mingled with the particles of coal. A fire of coal or other fuel must be built on a hearth in front of the mouth of the pipe E', and as the fan E forces the' pulverulent fuel over this fire it will be ignited and burned while iioating in the air. Gas, atmospheric air, petroleum, or other liquid may be introduced in regulated quantities and as needed through the openings at O1 O2 &c.,

i so as to change or modify the character of the flame according to the requirements of the operation. In cases where the fuel has to be driven into a furnace against a pressure, an adequate pressure must be given to the air, gas, steam,

.&c., passing out ofthe pipe E to overcome such pressure.

lI am aware that the system of burning nelypulverized coal in furnaces into which it is injected by suitable mechanism is very old. I am also aware that revolving fans or wings have been used for the purpose of feeding pulverized fuel into furnaces. I am also aware that spiral conveyers have been used for carrying the fuel out of the hopper. I am also aware that fuel has been fed in with the blast createdby a fanblower to be burned while floating in the air; and also that steam has been used for the purpose of injecting pulverulent fuel, having myself presented an application on such an apparatus heretofore passed for issue. But my invention is distinguished from all others in this, that several revolving fans for the various purposes have not heretofore been combined and arranged as I propose to claim them, it being the new combination and arrangement that I claim, not any 'of the elements or parts so combined, all of which are very old. And also in this, that in my apparatus every possible care is taken that no air whatever shall enter the fan-case with the pulverulent fuel that can possibly be excluded; whereas in other machines, heretofore used for the purpose, the fuel has been fed in the case of a fan-blower with the air which supplies the blast 3 such mode of supplying the air being, in my opinion,fatal to the system in many useful applications. And also in this, that the waste steam which has given motion to the fuel-thrower and fan-blast is utilized for the purpose of injecting air into the furnace mingled with the pulverized fuel after the latter has been thrown from the fan-case, which air, and also gases or liquids, may be supplied in quantities perfectly within the control of the operator. In calling the winged Wheel E a fan I have not desired to be understood as describing it to be a fan for the creation of apressure-blast,

such not being at all its function; it is merely a fuel-thrower, and whatever action it has besides this is in its tendency to create a vacuum in the fan-case, thereby bringing the atmospheric pressure into operation on the surface of fuel in the hopper, thereby tending to force in the fuel, but without air, for the hopper must be kept supplied with the powdered fuel.

What I claim as my invention, and desire to secure by Letters Patent, is

l. In combination with the fuel-feeder for supplying comminuted fuel, the fans G E and F, arranged to operate in separate compartments in relation to each other, substantially in the manner set forth.

2. In combination with the hopper, fan-case, and fan for driving forward the pulverulent fuel, a pipe, L, for connecting the hopper with the fan-case, substantially as set forth.

3. The arrangement of the pipes M and E in relation to the fan E and its case, substantially as and for the purpose set forth.

4. In combination with the case and fan E, and exit-pipe E', openings O1, Svc., arranged substantially as and for the purpose set forth.

5. The combination and arrangement of the hopper, pipe L, fan E and its case, pipe E', and openings tolfallo'w the intermingling of air, &c., in regulated quantities with the purverulent fuel onlyl after it has passed out of the case, substantially as set forth. 4

In testimony whereof I have signed my name to this specification in thepresence of two sub scribing witnesses.

JOHN Y. SMITH.

Witnesses:

R. MASON,

B. Einw. J EiLs. (99) 

